The present invention pertains to an improved strapping tool. More particularly, the present invention pertains to a strapping tool that accommodates strapping material of varying widths and thickness, and facilitates operation in more than one orientation.
Strapping machines or strappers are well known in the art. The machines are used to strap together articles, e.g., a load, with strapping material. Strapping material is offered in a variety of sizes and materials and is generally stored on a roll. Conventional strapping materials include plastic and metals, such as steel. Steel strapping is typically coated with, for example paint, to inhibit corrosion.
Typically, a free end of strapping material is passed around the load until there is an overlap between the free end and the strapping material still connected to the roll. The overlapping portion of strapping material is placed between jaws of a strapping machine and the free end of the strapping material is fixed in place by a gripper portion of the machine. After the strapping material is fixed, the material is generally tightened or tensioned around the articles to a desired tension. This is accomplished by operating a feed wheel to pull back or tension the strapping material.
A typical strapping machine includes sealing heads for sealing the free end of the strapping material onto itself, around the load. Typically, in manual (i.e., hand-operated) strapping machines, a handle is rotated which applies a force to cause a punch or sealing head to engage and press down against the strap to seal the strap to itself. After the strapping material is sealed, the strapping material still connected to the roll is cut by a cutter, which is a portion of the strapper. This completes one strapping operation.
In one known type of strapper, the sealing head and the cutter are carried by a jaw assembly within the strapper. The jaw assembly includes a stationary or fixed sealing head, a movable sealing head and the cutter. The cutter moves with the movable sealing head into and out of engagement with the strap material to form the seal and cut the strap from the roll or supply. Typically, the movable portion of the jaw is actuated by rotation of an actuator handle. The handle rotates about a shaft that is positioned within the strapper body.
Although straps are typically available having standard widths and thicknesses (i.e., gauges), there are tolerances within which the strap may be supplied. This is particularly the case with respect to the strap gauge. Strap is typically available in standard thicknesses of xc2xd inch, ⅝ inch and xc2xe inch.
To this end, strappers are required to properly function with varying thicknesses and widths of strap. Thus, whenever a xe2x80x9cnewxe2x80x9d source of strap is supplied, such as when a new roll of strap is used, the sealing head height can require adjustment.
In one arrangement for adjusting the tool to accommodate varying thicknesses of strap, the shaft on which the actuator handle is positioned is eccentrically formed. In this manner, the portion of the handle that is positioned with the strapper body has one axis of rotation and the portion on which the jaw assembly is mounted has different axis of rotation. This permits adjusting the distance that the movable sealing head moves relative to the fixed sealing head, and thus permits adjusting the gap between the sealing heads when the heads are fully engaged.
To fix the position of the shaft, a hexagonal key extends from an end of the shaft. A plate having a key-way with a mating hexagonal opening is fitted over the key and is secured in place to the strapper body by a fastener that is inserted though a notched opening in the plate. The plate can be rotated such that the fastener rides through the notched opening to rotate the shaft for adjusting the shaft position (and thus the height of the movable sealing head).
Although this arrangement permits readily adjusting and setting the sealing head height (by rotating the shaft through 360xc2x0), because the key and key-way are hexagonal shaped, the key can fit into the key-way in any one of six positions. While this provides flexibility in adjusting the sealing head height, it also creates the possibility (and probability) that the key will be improperly set within the key way, thus improperly setting the height of the movable head relative to the fixed head.
In an arrangement for accommodating varying strap widths, one strapper uses a simple, removable stop plate against which the strap rests when it is fully inserted into the jaw assembly. In one position, the plate is configured to accommodate one width of strap, and when removed, the strapper accommodates another size of strap. Thus, only two of the three xe2x80x9cstandardxe2x80x9d widths are accommodate by any one strapper without major reconfiguration and changes to the tool.
In addition, due to awkwardly shaped loads, it may be easier to perform strapping operations in different orientations. This is particularly so given that the strapper is often used xe2x80x9cin the field,xe2x80x9d from locations ranging from logging sites to large indoor warehouse facilities. As such, the strapper may be operated with the jaw residing horizontally, vertically or even at an incline between the horizontal and vertical. To this end, the orientation and position of the actuating handle can be different throughout use at any given site or location.
Accordingly, there continues to be a need for a strapper machine that can be readily adjusted to accommodate strap material of varying widths and thicknesses. Desirably, such strapper accommodates strap material of varying thicknesses, such as when rolls of material are changed out, with minimal effort. More desirable, such a strapper further permits maintenance on the strapper head or jaw while maintaining a predetermined setting for the strap thickness.
Additionally, such a strapper can accommodate any of the three standard strap widths with minimal adjustment. Desirable, such a strap width adjustment is carried out by movement of parts within and part of the strap width setting assembly. Moreover, such a strapper further accommodates operation an a variety of orientations and positions so as to reduce operator fatigue and to improve leverage in operation of the actuator handle.
A strapping machine forms a seal between two portions of strapping material and cuts an upper layer of the strapping material without impinging a lower layer of the strapping material. The strapping machine includes a strapping machine body having first and second shaft apertures formed therein. The body further includes first and second fastener apertures formed in the body adjacent one of the shaft apertures.
An eccentric shaft includes first and second shaft sections integral with one another defining primary and secondary axes of rotation. Preferably, the first shaft section defines two sections, each defining the primary axis of rotation.
The second shaft section is eccentric relative to the first shaft section, and defines the secondary axis of rotation. The axes are spaced from and parallel to one another. The shaft is positioned in the body with the first shaft sections in the shaft apertures for rotation therein. To effect the eccentricity in the shaft, the shaft sections can have equal or different diameters with different axes of rotation. A key extends from an end of the first shaft section.
The machine includes a fixed support and a movable support. The movable support includes a cutter mounted thereto and is movable away from and toward the fixed support to form the seal and cut the upper layer of strapping material. The movable support is movable toward the fixed support to a define desired clearance therebetween.
An actuating lever is rotatable about the eccentric, second shaft section. The actuating lever is operably connected to the movable support for moving the movable support toward and away from the fixed support.
A shaft securing member has a key receiving aperture that is configured for engagement with the shaft key in only one orientation. The shaft securing member is fastened to the body to secure the shaft in a desired orientation. The securing member has at least one fastener opening therein for alignment with one of the first and second apertures in the strapping machine body.
The shaft is rotated to a position to set the desired clearance between the movable and fixed supports. The shaft securing member is engaged with the shaft and is fastened to the strapping machine body to secure the shaft at that rotated position. The shaft is removable from the body and replaceable only at that rotated position.
In a present embodiment, shaft key has a square shape having a corner removed, and the key receiving aperture has a corresponding square shape having a corner removed.
The shaft securing member can be formed as a wedge-shaped plate that fastens to the machine body. The key receiving aperture can be formed at about an apex of the plate. The shaft securing member fastener opening can be formed as an elongated opening or slot. Preferably, the fastener opening can be formed as an elongated opening having an arcuate shape having a focus at the key receiving aperture.
Alternately, the shaft securing member fastener opening is formed as a series of adjacent fastener openings formed as a series of adjacent fastener openings lying along an arcuate path having a focus at the key receiving aperture.
The actuating lever can include a pivot portion and a reversible handle. The handle has a straight segment and an angled segment. The reversible handle is removably connected to the pivot portion and can be secured to the pivot portion in a first orientation in which the angled segment extends in a first direction and a second orientation opposite the first orientation. The handle can be secured to the pivot portion by fasteners.
The strapping machine can further include a variable strap width accommodating assembly. The variable width assembly includes outside and inside guides to secure and hold the strapping material between the fixed and movable supports during the sealing and cutting operation.
The outside guide includes first and second guide elements pivotally connected to one another. The outside guide is removably connected to the strapping machine body. The first and second guide elements have different thicknesses relative to a plane defined generally by the strapping material between the fixed and movable supports. The outside guide elements are configured to pivot so that one is positioned in a depending orientation relative to the other.
An inside guide is mounted to the strapping machine body intersecting the strapping material plane. The depending outside guide element guide is moveable into the strapping material plane to abut the strapping material and position the strapping material between the inside and outside guides when the movable support is moved toward the fixed support for forming the seal.
In a present configuration, the outside guide first and second elements are pivotally mounted to one another by a pivot pin. The entire outside guide is mounted to the strapping machine body by the pivot pin.
The non-depending outside guide element is positioned in a longitudinal orientation relative to the depending guide element. The longitudinally oriented element is further mounted to the strapping machine body by a pin connecting the longitudinal guide element to the strapping machine body to secure the outside guide to the body.
The inside guide defines first and second guide edges and is connected to the strapping machine body at a point of connection. The point of connection is a first distance from the first guide edge and a second distance from the second guide edge, different from the first distance.
Apertures are formed in the inside guide and the strapping machine body at the point of connection. A fastener secures the guide to the strapping machine body.
Advantageously, the inside and outside guides are independently positionable on the strapping machine body. To this end, the machine accommodates at least three different strapping material widths.
Other features and advantages of the present invention will be apparent from the following detailed description, the accompanying drawings, and the appended claims.